It would be a good analysis if the level of the top practitioners remained constant through the ages. However, it seems that aikido does not impress the world of martial arts the way it did before the war.

Why is that ? Here are a few possible explanations :
1- The world of martial arts "caught up", and produced better practitioners, and now fares better compared to aikido.
2- The sheer number of beginning and intermediate level aikido practitioners (due to its worldwide spread) offsets the quality of the aikido elite, that remained constant over the years.
3- aikido transmitted pretty much as completely as it was by O Sensei, but very few people now can afford practicing 6 hours a day, every day, with the same intensity as found in the Kobukai, and living the very formative life of ushi-deshi.
4- Some essential teachings of aikido are not transmitted anymore, which means the quality of today's aikido (even at the top level) is lower than it was decades ago.

I don't have the answers(s), but this community is a good place for that debate.